Tiling over different surfaces

Jenny Morgan · 01-28-2009, 04:33 AM

I'm just about to get my kitchen done, including the floor being retiled. Following a subsidence problem, the floor level has dropped by about 6mm at one end of the room. The person coming in to do the tiling said that rather than take all the tiles up (there are two layers) he would remove those where the floor begins to decline (about 1/5 of the floor space) so that he has enough depth to concrete and level this area and then to tile over the whole lot so that the floor is flat again. Since I have had an issue with subsidence (hopefully now rectified) I am naturally concerned about any future movement. Will the fact that the new tiles (5 grade porcelain) are going over part tiled and part-concrete floor be a problem? I am just concerned that materials move differently. If this is okay, should he be using some kind of flexible adhesive, etc...?

Looking forward to hearing from you.

Thanks

Ron6519 · 01-28-2009, 08:55 AM

This described scenario is ill advised at best. All the tile layers should come up. Then the floor prepped for a new floor. What ever that needs.
Ron

**Termite** · 01-28-2009, 08:57 AM

I can tell you that flexible adhesive is probably the last thing you want. To maintain the integrity of the grout joints and the tiles themselves, a rigid base is needed...Thinset (like mortar) is probably more appropriate.

Personally I would remove all the tiles and use leveling mixture on the floor's low spots.

Moving this thread over to flooring where there are some flooring pros that can help you.